MORPHOLOGICAL RESPONSES AND MOLECULAR MODIFICATIONS IN TOMATO PLANTS AFTER MECHANICAL STIMULATION

Study of the growth responses of Lycopersicon esculentum (Mill. cv. VF N8) to mechanical stimulation applied to a single young internode show ed a rapid and sharp decrease in stem elongation and an inhibition of elongation of several internodes, indicative of information transmissi on in the plant, A new tomato cDNA partial clone encoding calmodulin w as isolated and used to study the time course of the gene induction in response to the rubbing treatment, Northern blot analysis showed a ma ximum accumulation of calmodulin mRNA 2 h after mechanical stimulation , not only in the rubbed internode, but also in upper and lower intern odes and in young leaves, Treatment of the plant with calcium and EGTA showed the involvement of calcium and, in particular, intracellular c alcium in calmodulin gene expression and cellular response.